Course
Date
JavaScript Tutorial
This JavaScript tutorial is crafted for beginners to introduce them to the basics and advanced concepts of JavaScript. By the end of this guide, you'll reach a proficiency level that sets the stage for further growth. Aimed at empowering you to progress towards becoming a world-class software developer, this tutorial paves the way for a successful career in web development and beyond.
Date Object
The Date object is a datatype built into the JavaScript language. Date objects are created with the new Date( ) as shown below.
Once a Date object is created, a number of methods allow you to operate on it. Most methods simply allow you to get and set the year, month, day, hour, minute, second, and millisecond fields of the object, using either local time or UTC (universal, or GMT) time.
The ECMAScript standard requires the Date object to be able to represent any date and time, to millisecond precision, within 100 million days before or after 1/1/1970. This is a range of plus or minus 273,785 years, so JavaScript can represent date and time till the year 275755.
Syntax
You can use any of the following syntaxes to create a Date object using
Date() constructor.new Date( )new Date(milliseconds)new Date(datestring)new Date(year,month,date[,hour,minute,second,millisecond ])Note − Parameters in the brackets are always optional.
Parameters
Here is a description of the parameters −
- No Argument − With no arguments, the Date() constructor creates a Date object set to the current date and time.
- milliseconds − When one numeric argument is passed, it is taken as the internal numeric representation of the date in milliseconds, as returned by the getTime() method. For example, passing the argument 5000 creates a date that represents five seconds past midnight on 1/1/70.
- datestring − When one string argument is passed, it is a string representation of a date, in the format accepted by the Date.parse() method.
- 7 agruments − To use the last form of the constructor shown above. Here is a description of each argument
Return value
It returns the date string containing day, month, date, year, hours, minutes, seconds, and timezone.
Date Properties
Here is a list of the properties of the Date object along with their description.
In the following sections, we will have a few examples to demonstrate the usage of different Date properties.
Date Methods
Here is a list of the methods used with Date and their description.
Converts a date to a string, using the universal time convention.
Date Static Methods
In addition to the many instance methods listed previously, the Date object also defines two static methods. These methods are invoked through the
Date() constructor itself.In the following sections, we will have a few examples to demonstrate the usages of Date Static methods.
Examples
Example: Creating JavaScript Date Object
In the example below, we create a new instance of the date object. In the output, you can observe that it returns the current time.
<html><head> <title> JavaScript - Date object </title></head><body> <p id = "output"> </p> <script> const date = new Date(); document.getElementById("output").innerHTML = "Today's date is : " + date; </script></body></html>If we execute the above program, it returns the current time.
Example: Setting up custom date
In the example below, we have passed the custom date string as a parameter of the Date() constructor to create a custom date.
The
Date() constructor returns the standard date string, which you can see in the output.<html><head> <title> JavaScript - Date object </title></head><body> <p id = "output"> </p> <script> const date = new Date("August 19, 2024 09:30:54"); document.getElementById("output").innerHTML = "The custom date is : " + date; </script></body></html>If we execute the above program, it returns the custom time as provided.
Example: Passing argument in milliseconds
In the example below, we have passed milliseconds as an argument of the Date() constructor. If you pass the positive milliseconds as an argument, the object returns the date according to the 1st January 1970 00:00:00 + milliseconds.
Otherwise, it returns the date according to the 1st January 1970 00:00:00 – milliseconds if negative milliseconds passed as an argument.
<html><head> <title> JavaScript - Date object </title></head><body> <p id = "output"> </p> <script> const output = document.getElementById("output"); let date = new Date(999999999999); output.innerHTML += "The Date after 1st January, 1970 is - " + date + "<br>"; date = new Date(-999999999999); output.innerHTML += "The Date before 1st January, 1970 is - " + date; </script></body></html>It returns the date after 1st January, 1970 and before 1st January, 1970 as result.
Example: Constructing a date from 7 arguments
In the example below, we have passed the year, month, date, hour, minute, second, and millisecond as a Date() constructor argument. The Date() constructor returns the full date string, which you can see in the output.
<html><head> <title> JavaScript - Date object </title></head><body> <p id = "output"> </p> <script> const date = new Date(2001, 5, 14, 6, 43, 58, 342); document.getElementById("output").innerHTML = "The custom date is : " + date; </script></body></html>If we execute the above program, it returns the custom time as provided.
However, you can use the different methods of the Date object to format the date string. Let’s look at the example below.
Example: Formatting a date string
In the example below, three different methods are used to format the date string.
The
toDateString() method extracts the date only from the date string and removes the time part.The
toISOString() method converts the date string into the ISO format.The
toUTCString() method converts the date string into the UTC time format.<html><head> <title> JavaScript - Formatting the date </title></head><body> <p id = "output"> </p> <script> const date = new Date(999999999999); document.getElementById("output").innerHTML += "The Date after 1st January, 1970 is: " + date.toDateString() + "<br>"+ "The Date after 1st January, 1970 is: " + date.toISOString() + "<br>"+ "The Date after 1st January, 1970 is: " + date.toUTCString(); </script></body></html>It will return the ouptut of the above provided methods, respectively.